Need help tweaking 128Kbps cable connection

TeenInternetAddict · Post by **TeenInternetAddict** » Mon Jul 05, 2004 8:21 pm

Good evening, everyone! I have downgrade from 3000/256 to 128/128 because 128Kbps cable is a lot more cheaper from Cox than their 3Mbps service if you're on a budget. Well, I need help tweaking my registry for 128Kbps cable. I'm using a Terayon TJ715x hooked up by Ethernet. The ethernet drivers is up to date.

1. I have Tcp Optimizer.

2. Windows XP Home Edition

3. Here's a TCP Analyzer:

TCP options string = 020405b401010402
MTU = 1500
MTU is fully optimized for broadband.
MSS = 1460
Maximum useful data in each packet = 1460, which equals MSS.

Default Receive Window (RWIN) = 17520
RWIN Scaling (RFC1323) = 0 bits
Unscaled Receive Window = 17520

RWIN is a multiple of MSS
Other values for RWIN that might work well with your current MTU/MSS:
513920 (MSS x 44 * scale factor of 8)
256960 (MSS x 44 * scale factor of 4)
128480 (MSS x 44 * scale factor of 2)
64240 (MSS x 44)
bandwidth * delay product (Note this is not a speed test):

Your RcvWindow limits you to: 700.8 kbps (87.6 KBytes/s) @ 200ms
Your RcvWindow limits you to: 280.32 kbps (35.04 KBytes/s) @ 500ms
Consider increasing your RWIN value to optimize TCP/IP for broadband.
MTU Discovery (RFC1191) = ON
Time to live left = 118 hops

TTL value is ok.
Timestamps (RFC1323) = OFF
Selective Acknowledgements (RFC2018) = ON
IP type of service field (RFC1349) = 00000000

4. I'm on cable

5. Cox HSI, capped at 128Kbps down and 128Kbps up.

6. No router, Windows firewall

Here's a speed test using Windows XP's default RWIN at 17250:

2004-07-05 20:16:30 EST: 133 / 150
Your download speed : 137056 bps, or 133 kbps.
A 16.7 KB/sec transfer rate.
Your upload speed : 154202 bps, or 150 kbps.

I find that things are faster at the Default settings than using 5840 or 7300. Thank you for any assistance given

to anyone that could help me.

TeenInternetAddict

mnosteele52 · Post by **mnosteele52** » Mon Jul 05, 2004 9:42 pm

Try these CableNut settings:

DefaultReceiveWindow = 16384
DefaultSendWindow = 16384
DisableAddressSharing = 1
InitialLargeBufferCount = 20
InitialMediumBufferCount = 48
InitialSmallBufferCount = 64
LargeBufferSize = 81920
MaxFastTransmit = 6400
MediumBufferSize = 15040
PriorityBoost = 0
SmallBufferSize = 1280
TransmitWorker = 32
FastSendDatagramThreshold = 1024
EnableFastRouteLookup = 1
EnablePMTUDiscovery = 1
IgnorePushBitsOnReceive = 0
GlobalMaxTcpWindowSize = 17520
MaxFreeTcbs = 8000
MaxHashTableSize = 16384
MaxNormLookupMemory = 5000000
SackOpts = 1
SynAttackProtect = 1
Tcp1323Opts = 0
TcpLogLevel = 1
TcpMaxDupAcks = 2
TcpMaxHalfOpen = 100
TcpMaxHalfRetried = 80
TcpRecvSegmentSize = 1460
TcpSendSegmentSize = 1460
TcpTimedWaitDelay = 30
TcpUseRFC1122UrgentPointer = 0
TcpWindowSize = 17520
MaxConnectionsPer1_0Server = 8
MaxConnectionsPerServer = 4
DefaultTTL = 128
DisableUserTOSSetting = 0
TcpMaxDataRetransmissions = 6
DefaultTOSValue = 240

TeenInternetAddict · Post by **TeenInternetAddict** » Mon Jul 05, 2004 11:11 pm

Webpages are loading faster and your tweaks did work!

Here's a speed test using your settings:

2004-07-05 22:58:45 EST: 134 / 149
Your download speed : 137229 bps, or 134 kbps.
A 16.7 KB/sec transfer rate.
Your upload speed : 153286 bps, or 149 kbps.
test IP was to cox.net via gnaps.net

Here's another TCP/IP Analyzer test result:

TCP options string = 020405b401010402
MTU = 1500
MTU is fully optimized for broadband.
MSS = 1460
Maximum useful data in each packet = 1460, which equals MSS.

Default Receive Window (RWIN) = 17250
RWIN Scaling (RFC1323) = 0 bits
Unscaled Receive Window = 17250

For optimum performance, consider changing RWIN to a multiple of MSS.
Other values for RWIN that might work well with your current MTU/MSS:
513920 (MSS x 44 * scale factor of 8)
256960 (MSS x 44 * scale factor of 4)
128480 (MSS x 44 * scale factor of 2)
64240 (MSS x 44)
bandwidth * delay product (Note this is not a speed test):

Your RcvWindow limits you to: 690 kbps (86.25 KBytes/s) @ 200ms
Your RcvWindow limits you to: 276 kbps (34.5 KBytes/s) @ 500ms
Consider increasing your RWIN value to optimize TCP/IP for broadband.
MTU Discovery (RFC1191) = ON
Time to live left = 118 hops

TTL value is ok.
Timestamps (RFC1323) = OFF
Selective Acknowledgements (RFC2018) = ON
IP type of service field (RFC1349) = 00000000

Thanks, Mnosteele52. Your settings does work and I'm going to go leave stuff alone and surf on. I'm going to try the faster webpage tweak and other tips in your help link. Thanks very much!

mnosteele52 · Post by **mnosteele52** » Tue Jul 06, 2004 6:01 am

Great, glad to help.